3 6 TJiC Irish Naturalist. [February, 



and non-sexual vegetations by not giving enough time for 

 shutting off the later oogonia or zoosporangia from the 

 supplies (by the growth of their basal walls or septa), and 

 so causing involved vegetation to arise, of intermediate 

 morpholog3^ Ii^ ^^^Y cultivation of L. bandoiiiensis an early 

 oospore production was followed by a vigorous zoospore 

 vegetation, and as a final effort unusual chlamydospores of 

 the most complete form were developed on stout lateral 

 branches. They were of globular shape, and germination 

 took place without delay by the growth of a large germ-hypha, 

 inside which was produced a second filament carrying a 

 terminal clavate sporangium (fig. 7), w^hich liberated as active 

 zoospores all the contained material of the mother-cell. 



A few terminal " resting sporangia " of varying shape were 

 also produced, which liberated their zoospores through an 

 opening, as in Saprolegnia, or through short germ-like 

 outgrowths. 



The non-sexual fruit was produced from the ordinary 

 filamentous zoosporangia, and from the chlamydospores at 

 the same time, and continued until one and all were empty, 

 which occurred on the eighth day of cultivation. 



The large globular chlamydospores were produced from 

 oogonial origins, which w^ere developing at the time when 

 sexual vegetation began to fail, and their later changed 

 development was probably induced by their being overtaken 

 by a plasma of changed differentiation, their basal walls being 

 5-et unformed. The reason why chlamydospores are usually 

 terminal (sporangial) would thus appear to be due to the non- 

 sexual fruit being generally first produced, whence it may 

 follow that zoospores are developed owing to non-sexual 

 material being enclosed in them. Observers, however, must 

 have noticed in old cultivations of Saprolegnia fcrox, the rarer 

 development of oospores within a zoosporangium, or close to 

 it, in the filament to which it belonged ; in this case the vessel 

 must have been emptied of its earlier plasma by zoospore 

 liberation before the later oospore vegetation set in. 



I regard my observations on the life-history of Z. ba7idonie7isis 

 as being very incomplete. Little is known of the influences 

 which control spore-production in the Saprolegniacese, and 

 the reversion of the usual order in L, ba7ido?iie?isis, by which 



